JPH01273231A - Driving device for information recording and reproducing - Google Patents

Abstract

PURPOSE:To obtain an information recording and reproducing driver, which is of high rigidity with less fluctuation and capable of making high speed access, by forming integrally a coil anchored with an adhesive with a driving member by molding. CONSTITUTION:The coil 31 has an air-core and is anchored by vacuum impregnation of a resin 32, e.g., a borosiloxane inorganic polymer, etc. Then, the coil 31 is set in a mold, into which a resin 33 is poured to form a bobbin 34. By this structure, the resin 33 can be thin. For the resin 33, polyphenylene sulfide as a main material filled with carbon fibers in >=20%, with moreover an additive of some sort of inorganic fibers is an ideal material. A plural number of coils 31 is also applicable, and in this case, the resin 33 is filled in between the coils 31 to form a rib structure, so that the rigidity is increased. By this constitution, the coil is of high rigidity, thus decreasing fluctuations, and capable of responsing to the high access movement.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is used in an optical information recording/reproducing device that records, reproduces, or erases information by, for example, irradiating a disk-shaped recording medium with a light beam. The present invention relates to an information recording/reproducing drive device.

[Prior Art] With the recent development of optoelectronics, optical information recording and reproducing devices that can randomly record, reproduce, or erase audio or image information with high performance using a light beam such as a laser beam have become available. has been done. An example of such a device is an optical video disk device, which uses an optical head to detect recorded information consisting of protrusions or concave patterns on a disk-shaped recording medium made of transparent acrylic resin, etc. in digital quantities, and performs photoelectric conversion. After that, the gain is appropriately adjusted by an amplifier, and further converted into a predetermined analogue value via a reproducing circuit such as a D/A converter, and then output to an output device such as a speaker or CRT. In this way, desired audio or color images can be obtained instantaneously and with high performance.

In the conventional optical information recording and reproducing device as described above,
An optical head for recording, reproducing, or erasing information has a configuration shown in FIG. 7, for example. In this Figure 7,
A-A' force direction indicates the radial direction of a disk-shaped recording medium (not shown), and B-B' force direction indicates the vertical direction, that is, the direction of gravity. The optical head 2 has a box-shaped carriage 3.

An objective lens 4 is supported on the carriage 3 so as to be movable in the focus direction, that is, in the B-B' length direction, and in the tracking direction, that is, in the A-A' force direction, with respect to the recording surface of the disk-shaped recording medium. A lens actuator 5 is provided to drive in each direction. Further, the optical head 2 is mounted on the base 6 with holding plates 7a, 7b, 7c, and 7d.
It is supported by two guide rails 8a and 8b which are fixed to each other, and is movable in the A-A' force direction by a linear motor 9. This linear motor 9 includes a pobbin 11 having a coil 10 wound around its outer periphery and fixed to the carriage 3;
The electromagnetic yoke 13 is made of a ferromagnetic material to which at least one permanent magnet 12 is fixed. A linear sensor 14 is provided on the upper part of the carriage 3, and this linear sensor 14 has a groove 14a, and a linear encoder plate 15 fixed to the base 6 is sandwiched in the groove 14a in a non-contact manner. The linear encoder plate 15 has a plurality of slits 15a, and these slits 15a are provided to detect the position of the optical head 2. When the optical head 2 moves, the linear sensor 14 is connected to the linear encoder plate 15. 15a by irradiating light from the light emitting part of
The position of the optical radar 2 is detected by counting the number of light leaking from the light receiving section of the linear sensor 14. Note that during recording and reproduction, the disk-shaped recording medium is rotated at high speed by a spindle motor 16.

In this way, the conventional optical information recording/reproducing device uses the linear sensor 14 and the linear encoder plate 15 to control the optical head 2.
While confirming its position, the RAD 2 is moved to access the optical system while controlling the current of the coil IO using the linear motor 9.

However, as shown in FIG. 8, simply winding the coil 10 around the pobbin 11 of the linear motor 9 cannot withstand high-speed access movement, and the pobbin 1 including the coil 10
It is difficult to improve the rigidity of coil 1.
Even if the wire is impregnated with varnish and fixed to the pobbin 11 with adhesive, etc., the pobbin 11 often resonates due to lack of rigidity when the linear motor 9 operates. There is also significant fluctuation in the operating characteristics.

The rigidity of Pobin ll itself is made of aluminum, ceramics,
This can be improved by using non-magnetic stainless steel, but if metal is used, its specific gravity (for example, AN: 2.7, Fe-nea, 8
) is large, resulting in an increase in weight and generation of eddy currents, which impede access movement. This eddy current can be eliminated, for example, by cutting the pobbin 11 into slits along line c-c' in FIG. Moreover, it is disadvantageous in terms of moldability.

As described above, due to the lack of rigidity of the pobbin 11 including the coil lO, there is a problem in that it is not possible to access and move the radar 2 to the optical system at high speed.
There is a limit to the thickness of the film, making it difficult to make it thinner. In addition, conventionally used adhesives are epoxy adhesives and varnishes, but even though epoxy adhesives are heat resistant,
The varnish softens at about 150° C. and its adhesive strength drops significantly, and although varnish has good heat resistance, its adhesive strength is low and it is difficult to use.

Further, FIG. 9 shows a perspective view of the lens actuator 5 that drives the objective lens 4, and the objective lens holder 25 is inserted into a support shaft 28 fixed to a yoke 27 via a bearing 26. A weight 2 having approximately the same weight as the objective lens 4 is placed near the bearing 26 to maintain the weight balance with the objective lens 4.
9. Furthermore, a weight (not shown) is attached to maintain the weight balance in the vertical direction. A focusing coil 30 is wound around the outer periphery of the objective lens holder 25, and approximately elliptical focusing coils 31a, 31b,
31c and 31d (31c and 31d are not shown) are attached. Further, the yoke 27 is provided with tracking permanent magnets 32a and 32b so as to face the tracking coils 31a, 31b, 31c, and 31d.

32c and 32d are fixed respectively. Below these tracking permanent magnets 32a to 32d, focusing permanent magnets 33a and 33b are connected to the focusing coil 3.
It is attached so as to face 0. Furthermore, an inner yoke 34a serves as an opposing magnetic pole of the tracking permanent magnets 32a to 32d and the focusing permanent magnets 33a and 33b.
, 34b are provided on the objective lens holder 25.

However, since the focusing coil 30 and the tracking coils 31a to 31d are attached to the objective lens holder 25 by adhesive or other means as shown in the cross-sectional view of FIG. There is a problem that the rigidity is insufficient and it is difficult to drive the objective lens 4 at high speed.

[Object of the Invention] The object of the present invention has been made in view of the problems of the prior art described above, and is to provide a thin information recording/reproducing drive which is made of resin but has high rigidity and requires fewer molding steps. The goal is to provide equipment.

[Summary of the Invention] The gist of the present invention to achieve the above-mentioned object is to provide a drive device for driving a drive section in an information recording/reproducing device, which includes a drive member having a coil attached to its outer circumference, and a drive member having a coil attached to the outer circumference thereof. and a magnetic field generating means that is arranged at a distance to face the coil and generates a magnetic field that crosses the coil, the coil is an air-core coil impregnated with a heat-resistant adhesive, and the drive member is integrally formed with the coil by resin. This is an information recording/reproducing drive device characterized in that it is formed by molding.

[Embodiments of the Invention] The present invention will be described in detail based on embodiments illustrated in FIGS. 1 to 6. In addition, the same reference numerals in FIGS. 7 to 9 are the same.
or indicates an equivalent member.

1 is a perspective view of a pobbin of the linear motor 9, FIG. 2 is a perspective view of a coil, and FIG. 3 is a sectional view taken along the line T in FIG. 1. The coil 31 is wound and formed in advance as an air-core coil as shown in FIG.
A resin 32, such as a borosiloxane-based inorganic polymer, which is a liquid polymer whose main chain is an inorganic filler and is composed of lipolon, silicon, and oxygen, is impregnated into the gap between each winding wire by vacuum impregnation, and fixed. In this way, the molded coil 31 is positioned in the mold, and the pobbin resin 33 is poured in, and the pobbin 34 is formed by molding as shown in FIG.

In this case, the coil 31 and the bobbin 34 are integrally molded into a composite structure and have increased rigidity compared to the conventional joint state of two parts, so the thickness of the bobbin resin 33 can be reduced and the bobbin can be made thinner. The bobbin resin 33 to be used is preferably one made of polyphenylene sulfide (PPS) as a main material, filled with carbon fibers at a high content of about 20% or more, and further added with some inorganic fibers, for example, with a specific gravity of 1. 3~
Young's modulus is as low as 1.9 and 30.0X10-'kgr/
High, ctg2 or higher.

Although this embodiment shows the case where one coil 31 is used, a plurality of coils 31 may be used as shown in the sectional view of FIG. The resin 33 enters the rib structure, which further increases the rigidity.

Further, the bobbin resin 33 used in the examples is mainly made of PPS and highly filled with carbon lam, but is not limited to this. For example, the main material may be aromatic polyester, aromatic polyamide, Polyimide, LCP (liquid crystal polymer), PTFE, nylon 66, polycarpo, AB
S etc. can be used. As the filler, not only carbon fam but also glass fiber, organic fiber, etc. can be used. Further, the resin 32 for impregnating the coil 31 is not limited to the above-mentioned material as long as it is heat resistant and has high rigidity.

Furthermore, conventionally, a gap of about 0.5 mm is provided between the pobbin 11 and the electromagnetic yoke 13, but by using a sliding resin component such as Teflon for the pobbin 34, the pobbin 34 can be attached to the electromagnetic yoke 13. Slide to create a gap of 0.1 to 0.2
The thickness of the pobbin 34 can be increased by that much, or the number of turns of the coil 31 can be increased accordingly.

Although the above-described embodiment has been described using a bobbin for a linear motor 9 as a driving device, the present invention is not limited to this, and can also be applied to, for example, a lens actuator 5 that drives an objective lens 4 in two-dimensional or three-dimensional directions.

FIG. 5 shows the objective lens holder 4 of the lens actuator 5.
1, and FIG. 6 is a sectional view taken along the line -IV in FIG. 5. Tracking coils 42a, 42b
, 42c, 42d and the 7-orcus coil 43 are separately wound as an air-core coil, and further impregnated with varnish or a heat-resistant adhesive or heat-effect adhesive that can withstand the molding temperature as in the previous embodiment. stick. Each of the coils molded in this manner is positioned in a mold, and resin 44 having high rigidity is poured in as in the previous embodiment, and the objective lens holder 41 is integrally molded. As a result, the coil and objective lens holder 41 have a composite structure, and the rigidity is more than doubled.

[Effects of the Invention] As explained above, the information recording/reproducing drive device according to the present invention has a composite structure in which the coil fixed with adhesive is integrally formed with the drive member by molding.
It has high rigidity and less variation between products, making it possible to handle faster access movements.

[Brief explanation of the drawing]

1 to 6 show an embodiment of the information recording and reproducing drive device according to the present invention, in which FIG. 1 is a perspective view of a bobbin, FIG. 2 is a perspective view of an air-core coil, and FIGS. 3 and 4. 5 is a perspective view of a lens actuator, FIG. 6 is a sectional view thereof, FIG. 7 is a perspective view of a conventional optical head, and FIG. 8 is a perspective view of a conventional bobbin. FIG. 9 is a perspective view of a conventional lens actuator, and FIG. 10 is a sectional view of an objective lens holding member. 2 is an optical head, 4 is an objective lens, 5 is a lens actuator, 9 is a linear motor, 31, 42, 43 is a coil, 32, 33, 44 is a resin, 34 is a bobbin, and 41 is an objective lens holder. Patent applicant: Canon Co., Ltd.

Claims (1)

[Claims] 1. A drive device for driving a drive unit in an information recording/reproducing device, which includes a drive member having a coil attached to its outer periphery, and a drive member placed at a distance opposite to the coil to generate a magnetic field that crosses the coil. an information recording/reproducing device, characterized in that the coil is an air-core coil impregnated with a heat-resistant adhesive, and the driving member is integrally formed with the coil by molding of resin. Drive device.